it seems that no matter how i run the vacuum lines i can't get a consistent idle. it either hovers around 2500 or just climbs untill i turn the car off. it's a '90 si with a b18a1 swap. btw i'm running the civic si map sensor. anyone else who has done this swap please show me how you set your vacuum up

 

nothing?

 

Have you checked for vacuum leaks? Is your throttle cable adjusted properly?

 

get a bottle of brake cleaner and spray it around manifold to head area. throttle. and all lines, if idle gets better you have a leak.

a throttle cable DOES not And WILL not make a difference. YES you can tighten it up so it can run better BUT a engine should idle Perfect even with the cable unhooked. and the butterfly closed all the way.



Get a voltmeter
get a safety pin
stick it in the MIDDLE wire on your THROTTLE POSITION SENSOR.
Turn key all the way forward (DO NOT START CAR)
Loosen 2 screws hold tps sensor.
NOTE: they might be rivets. if so you must remove the throttle get a hack saw and saw the rivets,,creating a flat head screw.

I guarantee its off balance!!

It must be .5 at closed throttle and 4.5 At WIDE OPEN THROTTLE.

 

im pretty sure the tps is good, i just need to know how you set your vacuum lines up, that's what i don't know how to do. ls in an EF

 

You said the RPM just keeps climbing until youu shut the car off!

Thats not a vaccum issue. but ok

good luck

Go get a haynes manual and check vaccum routing

 

I had the same problem when I swapped in my b18a. I routed all vacuum lines as factory but still had a high idle. I did the DIY tb gasket out of a 24 pack of beer and it idled at a perfect 750 lol.

 

hmm, i might have to. it looks like the tb adjustment screw has been tampered with so i'll try that, and if that doesn't work i might as well replace the gasket.

 

for a slightly high idle try adjusting your throttle cable.

did you ever get the right vacuum routing? i could send you a pic if you didnt.

 

It definitely sounds like the type of problem that happens from an intake manifold gasket leak or an injector gasket leak.

Also block off the hose from the brake booster, perhaps your booster has failed and it's allowing air into the manifold.

You could also try swapping IACVs. Yours may be stuck open.

 

i was going to say that too.